Systems presently used on the west coast of British Columbia for collecting logs floating on a body of water comprise lassoing the logs in the water by means of steel cables and collecting them into bundles. This is usually done by a series of overhead steel cable rig lines strung between rig supports, and complementary steel cables which extend between the rig booms under the logs on the surface of the water.
In collecting the logs into bundles, the "belly" of the steel cables that extend under the surface of the water are moved to locations under floating tiers or rafts of logs. Stray logs, and clumps of logs, are "bulldozed" by one or more side winders into place over the "belly" of the cables extending under the water. Once the rafts and clumps of logs are in place, the steel cables are pulled taut to thereby collect and pull the logs into bundles for strapping with strap iron and loading onto a suitable shipping vessel.
A typical bundling machine is operated by Avalon Log Sort in Howe Sound, British Columbia. The bundling machine is mounted on a 40.times.90 wood barge equipped with two London two drum ship type cargo winches. An 80 ft. steel live boom is used for the purpose of pulling the bundling rigging out. The boom can be swung to the side while a tier of logs is pushed into place. However, hang-up problems with efficiency and smooth operation occur due to such things as the top line hanging up on tiers of logs while the boom is swung to the side and with the bottom line snagging on logs, etc., while the bundle is brought out of the water.
Also, problems occur from wheel wash created by the side winders. The wash causes log bundling band iron used for strapping bundles together to wrap and hang up on the bottom lines while placing a tier of logs in position. Raising the boom so that the side winder can go under the top line for the purpose of straightening up the tier does not solve the difficulty because the "belly" in the bottom line is then too shallow for placing the tier of logs.
Another problem which greatly reduces efficiency is that the wire cable bites into and holds the logs so that they cannot roll together snugly and evenly. Also, logs at angles in the tiers catch upon one another, and on the cables and this makes it impossible to turn out tight log bundles. A further problem is that after an eight hour shift, the bundling straps are kinked which further contributes to hang-ups.
This bundler is capable of putting out a bundle in six minutes provided there are no hang-ups. But the average is five bundles per hour because very few bundles go through without hang-ups.
Other problems associated with the present system using cables and rig booms, are that valuable wood in the outer logs of the bundle is damaged because the cable cuts into those outer logs. Moreover, as the logs are rolled against one another, bark rubs off the logs and drops to the bottom of the body of water. This causes environmental damage.
Further disadvantages are that the overhead cables, and cables extending under the water, represent a safety hazard to boats, pontoon equipped aircraft, and the like. Moreover, men working on the bundler sometimes get caught in the cables and are injured or thrown into the water.
The applicant is aware of the following patents which are considered relevant to this field of art.
______________________________________ Inventor ______________________________________ U.S. Pat. No. 3,033,397 Busch 3,452,887 Larson 3,452,888 Larson U.S.S.R. Patent No. 137,058 582,194 540,800 703,451 ______________________________________
Some of the references disclose a separate cable which is used to collect logs that are fed to the cradle by mechanical jaws.
U.S.S.R. Pat. Nos. 582,194 and 540,800 demonstrate apparatus that operate on a fork lift principle where the bottom prongs must be pushed under the logs and then the top of the jaw crushes the logs into bundles.
U.S.S.R. Pat. No. 703,451 discloses the use of a multi-linkage jaw gripper to stack timber. The gripper is not suitable for operation in water. The jaws move above the logs in order to form the logs into bundles.